Is there a role for marijuana in medical practice?: NO

Meldon Kahan; Anita Srivastava

Dr Ware states that cannabis has been used for thousands of years. Yet many time-honoured medical therapies are abandoned as it becomes evident that they are harmful or as they are replaced by more effective treatments. Dr Ware encourages family physicians to learn about the Marihuana Medical Access Regulations because physicians do not have to prescribe medical marijuana but simply to support its legal use. The access form might not be an official prescription, but patients will interpret the physician’s signature as an endorsement of the therapeutic benefits of smoked marijuana. Patients trust their physicians and expect physicians to act in their best interests; therefore physicians should sign the form only if they truly believe that medical marijuana is safer or more effective than available alternatives. This position is untenable now that oral and inhaled pharmaceutical cannabinoids are available.

Dr Ware admits that, although “cannabis has not yet been formally evaluated in clinical trials,” family physicians should become more familiar with it because studies are under way. Yet most clinical trials are testing pharmaceutical cannabinoids, not smoked marijuana. We are reassured that marijuana has “safety data generated from 2 generations of recreational users.” This statement is unreferenced, and we take issue with Dr Ware’s commonly held view that cannabis is a harmless herbal remedy. Its harms are well studied and documented; marijuana smokers are likely at increased risk of prostate, head, and neck cancers1; bronchitis2; motor vehicle accidents3; psychosis4,5; and psychosocial difficulties. Marijuana smoke contains numerous toxins, and the rapid delivery of high doses of inhaled delta-9-tetrahydrocannabinol puts smokers at risk of psychomotor impairment and addiction. It is inadvisable for family physicians to prescribe an unproven and possibly harmful substance to their patients when far safer alternatives are available.

Footnotes

These rebuttals are responses from the authors who were asked to discuss “Is there a role for marijuana in medical practice?” in the Debates section of the December issue (Can Fam Physician 2006;52:1531–3 [Eng], 1535–7 [Fr]). In these rebuttals, the authors refute their opponents’ arguments.

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